Non-factorisable contributions of strong-penguin operators in Λ b → Λℓ + ℓ − decays
Abstract We investigate for the first time a certain class of non-factorisable contributions of the four-quark operators O $$ \mathcal{O} $$ 3−6 in the weak effective Hamiltonian to the Λ b → Λℓ + ℓ − decay amplitude. We focus on the case where a virtual photon is radiated from one of the light cons...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2024-03-01
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| Series: | Journal of High Energy Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/JHEP03(2024)152 |
| Summary: | Abstract We investigate for the first time a certain class of non-factorisable contributions of the four-quark operators O $$ \mathcal{O} $$ 3−6 in the weak effective Hamiltonian to the Λ b → Λℓ + ℓ − decay amplitude. We focus on the case where a virtual photon is radiated from one of the light constituents of the Λ b baryon, in the kinematic situation of large hadronic recoil with an energetic Λ baryon in the final state. The effect on the suitably defined “non-local form factors” is calculated using the light-cone sum rule approach for a correlator with an interpolating current for the light Λ baryon. We find that this approach requires the introduction of new soft functions that generalise the standard light-cone distribution amplitudes (LCDAs) for the heavy Λ b baryon. We give a heuristic discussion of their properties and a model that relates them to the standard LCDAs. Within this framework, we provide numerical results for the size of the non-local form factors considered. |
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| ISSN: | 1029-8479 |